|Publication number||US6844851 B2|
|Application number||US 10/259,522|
|Publication date||Jan 18, 2005|
|Filing date||Sep 30, 2002|
|Priority date||May 27, 2002|
|Also published as||US20030218571|
|Publication number||10259522, 259522, US 6844851 B2, US 6844851B2, US-B2-6844851, US6844851 B2, US6844851B2|
|Inventors||Won-Sang Yoon, Gennadi Yevtyushkin|
|Original Assignee||Samsung Thales Co., Ltd.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (20), Non-Patent Citations (3), Referenced by (12), Classifications (29), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application claims priority to an application entitled “PLANNER ANTENNA HAVING LINEAR AND CIRCULAR POLARIZATION”, filed in the Korean Industrial Property Office on May 27, 2002 and assigned Serial No. 2002-29322, the contents of which are hereby incorporated by reference.
1. Technical Field
The present invention relates to an antenna that is located at the end of a wireless communication system, or other radio system, and more particularly, to a wideband planar antenna having linear and circular polarization, which uses different polarization for transmission and reception to increase the isolation between transmission and reception by suggesting and using a type of a radiation element.
2. Related Art
A dish antenna is commonly used for a satellite communication service because the dish antenna has a simple structure and it can easily form dual circular polarization. Dish antennas are sometimes cumbersome due to their bulkiness. For this reason, various kinds of planar array antennas with a low height have been introduced. However, most planar antennas can only utilize one of linear and circular polarization, not both.
This characteristic limits the use of the planar antenna such that the antenna cannot be used for both transmission and reception. In most cases, planar array antennas for satellite communication are used only for the purpose of reception.
I have found that there are disadvantages to current dish antennas and current planar antennas. Efforts have been made to improve antennas.
Exemplars of recent efforts in the art include U.S. Pat. No. 4,475,107 for CIRCULARLY POLARIZED MICROSTRIP LINE ANTENNA issued on Oct. 2, 1984 to Makimoto et al., U.S. Pat. No. 4,816,835 for PLANAR ANTENNA WITH PATCH ELEMENTS issued on Mar. 28, 1989 to Abiko et al., U.S. Pat. No. 4,614,947 for PLANNER HIGH-FREQUENCY ANTENNA HAVING A NETWORK OF FULLY SUSPENDED-SUBSTRATE MICROSTRIP TRANSMISSION LINES issued on Sep. 30, 1986 to Rammos, U.S. Pat. No. 6,166,701 for DUAL POLARIZATION ANTENNA ARRAY WITH RADIATIN SLOTS AND NOTCH DIPOLE ELEMENTS SHARING A COMMON APERTURE issued on Dec. 26, 2000 to Park et al., U.S. Pat. No. 5,241,321 for DUAL FREQUENCY CIRCULARLY POLARIZED MICROWAVE ANTENNA issued on Aug. 31, 1993 to Tsao, U.S. Pat. No. 6,107,956 for AUTOMOTIVE FORWARD LOOKING SENSOR ARCHITECTURE issued on Aug. 22, 2000 to Russell et al., U.S. Pat. No. 4,922,263 for PLATE ANTENNA WITH DOUBLE CROSSED POLARIZATIONS issued on May 1, 1990 to Dubost et al., U.S. Pat. No. 5,005,019 for ELECTROMAGNETICALLY COUPLED PRINTED-CIRCUIT ANTENNAS HAVING PATCHES OR SLOTS CAPACITIVELY COUPLED TO FEEDLINES issued on Apr. 2, 1991 to Zaghloul et al., and U.S. Pat. No. 5,321,411 for PLANAR ANTENNA FOR LINEARLY POLARIZED WAVES issued on Jun. 14, 1994 to Tsukamoto et al.
While these recent efforts provide advantages, I note that they fail to adequately provide an improved planar anntenna having linear and circular polarization.
To solve the above-described problems, it is an object of the present invention to provide an antenna having linear and circular polarization, which uses dipoles as radiation elements, and has an orthogonal characteristic in both linear and circular polarization, the antenna being embodied by using two plates and the front and back sides of the plates effectively.
An object of the present invention is to provide a planar antenna having linear and circular polarization, comprising: a plate with a conductor coated on both surfaces of a dielectric substance; a first branch positioned on a first surface of the plate; and a second branch positioned on a second surface of the plate.
Another object of the present invention is to provide a planar antenna having linear and circular polarization, comprising: a first plate with a conductor coated on both surfaces of a dielectric substance; a second plate with a conductor coated on both sides of the dielectric substance, the second plate being positioned under the first plate; a plurality of first symmetrical radiation elements which are on both surfaces of the first plate, for transmitting or receiving a radio wave; a plurality of second symmetrical radiation elements which are on both surfaces of the second plate, for transmitting or receiving a radio wave; a ground plate which supports the whole antenna and is used as a ground for the entire circuit; and a support for supporting the whole antenna by connecting the overlapped first and second plates and the ground plate.
Still another object of the present invention is to provide a radiation element comprising two branches and one stem, wherein the branches meet at the stem at an angle of 45° to the surface that is perpendicular to the stem, and the branches are in the shape of a symmetric dipole.
The present invention discloses a planar antenna that accommodates either linear or circular polarization having an orthogonal characteristic during transmission and reception in a wideband. By using two folds of printed-circuit-board type plates, the antenna of the present invention can minimize insertion loss, weight, and thickness. However, since isolated radiation elements are insufficient, the frequency band has a limitation.
The planar antenna of the present invention comprises a ground plate, two micro strip plates, and a support for connecting the ground plate and the micro strip plates. The space between the plates and the support is filled with a material such as polystyrene foam.
On each plate, there are dipoles, which are radiation elements, power supply circuits, slots, and stubs. The entire antenna is divided into rooms in the shape of a lattice, in which a ground circuit surrounds a pair of dipoles. The collection of lattice-shaped rooms is called a subarray. The subarrays positioned on the same surface have linear polarization characteristics independently from each other. Since the dipoles of each subarray are orthogonal to each other, the polarization vectors of two subarrays are orthogonal to each other. In addition, a subarray has an independent power supply circuit, and since the coupling of the orthogonal dipoles is very small, various forms of polarization can be embodied depending on how the subarrays are connected.
The power supply circuit in a single subarray includes a 90° phase shifter. Accordingly, the polarization of each of the subarrays combines to form circular polarization. The power supply circuit is connected to each of the subarrays and the power supply connections are orthogonal to each other. A termination of a subarray is connected to a circular waveguide through a probe, and it excites the Transverse Electric 11 (TE11) mode. Therefore, the two modes before and after the excitation are orthogonal to each other, and the overall mode is determined by overlapping the two modes. The polarization slope of the overall mode determines the correlations between the signal powers of orthogonal modes, and by the result of it, the polarization characteristic of an antenna is determined.
In other words, if Transverse Electric 11 (TE11) mode signals connected to the subarrays have the same linear polarization, the overall polarization has a characteristic of linear polarization, and if the phase difference of the Transverse Electric 11 (TE11) mode signals connected to the subarrays is 90°, the overall polarization has a characteristic of circular polarization. A single subarray has a characteristic of linear polarization.
To achieve these and other objects in accordance with the principles of the present invention, as embodied and broadly described, the present invention provides a planar antenna having linear and circular polarization, the antenna comprising: a plate having a dielectric substance with a conductor coated on side surfaces of the dielectric substance; and at least one radiation element comprising: a first branch being positioned on a first surface of said plate; and a second branch being positioned on a second surface of said plate different from the first surface.
To achieve these and other objects in accordance with the principles of the present invention, as embodied and broadly described, the present invention provides a planar antenna having linear and circular polarization, the antenna comprising: a first plate having a first dielectric substance with a conductor coated on side surfaces of the first dielectric substance, said first plate having a first side surface and a second side surface; a second plate having a second dielectric substance with a conductor coated on side surfaces of the second dielectric substance, said second plate having a first side surface and a second side surface, said second plate being under said first plate, said first side surface of said second plate facing said second side surface of said first plate; a plurality of first symmetrical radiation elements being on said first and second side surfaces of said first plate, said first elements performing at least one selected from among transmitting radio waves and receiving radio waves; a plurality of second symmetrical radiation elements being on said first and second side surfaces of said second plate, said second elements performing at least one selected from among transmitting radio waves and receiving radio waves; a ground plate corresponding to a local reference potential for said first and second elements, said ground plate being under said second plate; and a support supporting the antenna by connecting said first plate, said second plate, and said ground plate.
To achieve these and other objects in accordance with the principles of the present invention, as embodied and broadly described, the present invention provides a radiation element, comprising: a pair of branches; and a stem being joined to said pair of branches, each one of said branches forming a 45° angle with a surface that is perpendicular to said stem, said pair of branches corresponding to a symmetric dipole.
The present invention is more specifically described in the following paragraphs by reference to the drawings attached only by way of example. Other advantages and features will become apparent from the following description and from the claims.
In the accompanying drawings, which are incorporated in and constitute a part of this specification, embodiments of the invention are illustrated, which, together with a general description of the invention given above, and the detailed description given below, serve to exemplify the principles of this invention.
While the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the present invention are shown, it is to be understood at the outset of the description which follows that persons of skill in the appropriate arts may modify the invention here described while still achieving the favorable results of this invention. Accordingly, the description which follows is to be understood as being a broad, teaching disclosure directed to persons of skill in the appropriate arts, and not as limiting upon the present invention.
Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described. In the following description, well-known functions, constructions, and configurations are not described in detail since they could obscure the invention with unnecessary detail. It will be appreciated that in the development of any actual embodiment numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill having the benefit of this disclosure.
The present invention will now be described more fully with reference to the accompanying drawings, in which a preferred embodiment of the invention is shown. This invention may be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art. In the drawings, the thickness of the layers and regions are exaggerated for clarity. It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can either be directly on the other layer or substrate or has intervening layers present. The same reference numerals in different drawings represent the same elements, and thus their descriptions will be omitted.
One type of planar antenna can be associated with linearly polarize waves. Such an antenna can include a ground plate, power supply circuit plate, and radiation plate, and has a high gain, but it is used for the purpose of reception only.
Another type of planar antenna can be associated with circular polarization. Such an antenna is used for either transmission or reception due to its single polarization characteristic. Such an antenna will have a generally simple configuration. However, such an antenna does not embody the characteristic of dual polarization.
Some planar radiation elements can form both linear and circular polarization. An antenna that has linear and circular polarization may have all its radiation elements and power supply points existing on one plane, and a requested polarization is embodied by properly exciting in the power supply points. Accordingly, two power supply circuits are needed to obtain two kinds of polarization. This would be made possible by arraying the two power supply circuits appropriately on one plane.
A joint array could address some of the above-mentioned problems. An antenna that relates to a dual polarization antenna array using a common aperture can have the common aperture involving a micro strip dipole array and a plurality of centered slot arrays positioned in the aperture. Such a dual polarization array antenna could have radiation elements in the common apertures and multiple folds of power supply circuits.
Another antenna could have a fully suspended-substrate micro strip line, and two folds of power supply circuits for the common aperture of circular waveguide radiation elements. That type of antenna would be disadvantageous due to the complicated configuration, excessive height, and mechanically delicate fabrication process.
Another planar antenna could be formed of patch elements that make up a complete printed-circuit-board type dual polarization antenna. Such an antenna could be formed of a radiation element circuit unit, first and second power supply circuit units, and a ground plate stacked on one another, each layer being positioned independently by a dielectric substance layer. The patch elements of the radiation element circuit unit could be connected to the power supply circuit unit electromagnetically. Such a planar antenna could use a transmission signal or a reception signal in a different polarization mode, so that the polarization mode of transmission could be different from that of reception, and it could minimize loss so as to obtain high antenna gain.
In accordance with the principles of the present invention, the branches 110 and 120 are not required to form an angle that is 45° with the surface that is perpendicular to the stem 130. The branches 110 and 120 could form any angle less than 90° with the surface that is perpendicular to the stem 130.
As shown in
A circuit unit of the upper plate 210 is formed of a conductor, such as copper (Cu), aluminum (Al), silver (Ag), astatine (At), iron (Fe), and gold (Au), covering the surface of a dielectric substance. Since the side surfaces of the dielectric substance are covered with the conductor, radiation circuits are placed on both sides of the plates, just as a circuit is placed on a printed circuit board (PCB). Radiation circuit 260 is placed on the upper surface of the upper plate 210. Radiation circuit 270 is placed on the lower surface of the upper plate 210. Dielectric substances that can be used here include polyethylene, polyester, acrylic resin, polycarbonate, ammonium bicarbonate (ABC), polyvinyl chloride (PVC), and a mixture thereof. The dielectric substance has an upper side surface and a lower side surface.
The lower plate 220 and the upper plate 210 are formed in a similar manner. Radiation circuit 270 is placed on the upper surface of the lower plate 220. Radiation circuit 280 is placed on the lower surface of the lower plate 220. One part of radiation circuit 270 may be placed on the lower surface of the upper plate 210, and another part of radiation circuit 270 may be placed on the upper surface of the lower plate 220. In some cases, the entire radiation circuit 270 may be placed on the lower surface of the upper plate 210, or the entire radiation circuit 270 may be placed on the upper surface of the lower plate 220. Thus, if the entire radiation circuit 270 is placed on the lower surface of the upper plate 210, then the radiation circuit 270 does not exist on the upper surface of the lower plate 220.
The ground plate 230 is made of aluminum (Al). It supports the entire antenna and it is used as a ground of all of the circuits. The support 240 connects the two plates 210 and 220 and the ground plate 230. Within the support 240 exists a probe, and the probe is connected to the termination of the power supply circuit connected to the power supply circuit of each radiation element. A more detailed description will be provided with reference to FIG. 3.
Between the lower plate 220 and the ground plate 230 is a supporting substance such as polystyrene foam 250 for supporting the antenna. The supporting substance 250 also performs a function of insulating the ground plate 230 from the other plates 210 and 220.
A middle layer can exist between the lower surface of the upper plate 210 and the upper surface of the lower plate 220.
The upper plate 210 has an upper surface and a lower surface. The upper and lower surfaces of the upper plate 210 can be referred to as an upper side surface and a lower side surface, or can be referred to merely as side surfaces of the upper plate 210.
The lower plate 220 has an upper surface and a lower surface. The upper and lower surfaces of the lower plate 220 can be referred to as an upper side surface and a lower side surface, or can be referred to merely as side surfaces of the lower plate 220.
The items in
The 16 radiation elements in
The radiation elements located at both sides of the plates are in the form of a symmetrical dipole. One branch 310 of the dipole lies on one surface of the upper plate 210 with the power supply wire 320, and the other branch 350 a lies on the ground circuit 360, which is on the opposite surface of the upper plate 210. Accordingly, one branch 310 of the dipole and the other branch 350 a corresponding thereto are located at opposite surfaces of a plate 210. That is, a subarray has dipoles arranged on one side of a plate 210 as shown in FIG. 4 and another subarray has dipoles arranged on the other side of the plate 210 as shown in
The other plate 220 is just the same as the plate 210 described above. In other words, one branch 330 of the dipole lies on one surface of the plate 220 with the power supply wire 340, and the other branch 350 b lies on the ground circuit 360, which is on the opposite surface of the plate 220. Accordingly, one branch 330 of the dipole and the other branch 350 b of the same dipole are located on opposite sides of a plate 220. That is, a subarray has a shape in which the dipoles of FIG. 6 and the dipoles of
The power supply wires 320 and 340 are converted into micro strip lines through a balloon 370. A slot 380 is formed to compensate for the reactance of the dipole. It is formed in the shape of a groove where the branches of the dipole are bent. A stub 390 is formed to compensate for the coupling impedance, and it is positioned at the branch of the dipole. All the dipoles are supplied with power through the branch power supply wires, which diverge from the main power supply wire.
When the dipoles of
A power supply wire for one subarray is positioned on the upper plate 210, and a power supply wire for the other subarray is positioned on the lower plate 220. The ground circuit 360 is located between the two plates 210 and 220, and it is for both use for both subarrays.
The ground windows should be sufficiently thicker than the power supply wire to reduce the coupling between the power supply wires for the subarrays. The power supply circuit for each plate includes a phase shifter embodied with a micro strip line stub to have a phase difference of 90° with respect to the corresponding subarray. The phase shifter used here is a conventional phase shifter. In this case, when the two subarrays both operate, circular polarization can be obtained, whereas when only one subarray operates, linear polarization is obtained.
The termination 820 of the power supply circuit is located at the center of each plate, and the termination of the upper plate 210 is positioned to be orthogonal to the termination of the lower plate 220. The terminations 820 are connected to the probes 830 located at the center of the array antenna. Accordingly, all the subarrays include a pair of terminations in the same direction.
The pair of terminations is excited by the Transverse Electric 11 (TE11) mode of a circular waveguide combiner through the probes 830. When the two pairs of terminations 820 are orthogonal to each other, the two Transverse Electric 11 (TE11) modes become orthogonal to each other too.
Therefore, the two orthogonal Transverse Electric 11 (TE11) modes always correspond to two types of antenna polarization, i.e., linear (vertical or horizontal) polarization, or circular leftward or rightward polarization. One polarization is used for the purpose of transmission, and the other one is used for reception.
As described above, the present invention provides an antenna having linear and circular polarization, which has an orthogonal characteristic in both linear and circular polarization, and whose height can be lowered by embodying a micro strip planar antenna having dual polarization which has high gain over a wide frequency band, and transmits or receives linear or circular polarization.
While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant's general inventive concept.
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|US20120169561 *||Jul 5, 2012||Telekom Malaysia Berhad||450 MHz DONOR ANTENNA|
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|U.S. Classification||343/700.0MS, 343/810, 343/805, 343/795|
|International Classification||H01Q9/28, H01Q21/00, H01Q9/06, H01Q21/24, H01Q1/38, H01Q21/06, H01Q21/26, H01Q1/52, H01Q13/08|
|Cooperative Classification||H01Q21/24, H01Q1/525, H01Q9/285, H01Q1/38, H01Q21/062, H01Q9/065, H01Q21/0075, H01Q21/26|
|European Classification||H01Q21/24, H01Q21/26, H01Q1/38, H01Q21/00D6, H01Q9/28B, H01Q21/06B1, H01Q1/52B2, H01Q9/06B|
|Sep 30, 2002||AS||Assignment|
|Jul 28, 2008||REMI||Maintenance fee reminder mailed|
|Jan 18, 2009||LAPS||Lapse for failure to pay maintenance fees|
|Mar 10, 2009||FP||Expired due to failure to pay maintenance fee|
Effective date: 20090118